1. Field of the Invention
The present invention relates to an enclosed type lead battery used for the power source of portable equipment and, more particularly, to improvements in or relating to the jar or container thereof.
2. Statement of the Prior Art
The conventional enclosed type lead batteries so far produced include a synthetic resin-made jar having therein a stack consisting of positive plates, negative plates and a separator.
In recent years, there has been a growing demand for reducing the weight, size and thickness of the enclosed type lead batteries, as equipment using such batteries has increasingly been miniaturized. To meet such a demand, the structure that the stack of plates is wrapped in a film or sheet made of a synthetic resin has been proposed in the art. According to this proposal, the stack of plates is put between two films or sheets, the peripheral edges of which are then fused together to wrap it. The terminals are drawn out of the fused portion, while keeping airtightness at the same time. However, the terminal-confined portion should be subjected to special treatment and technique to make airtightness complete, and there are much uncertainties with regard to reliability due to the terminal portion being lacking in rigidity.